Injection engine



Feb. 6, 1940. POPE, JR 2,189,082

INJECTION ENGINE Filed Sept. 16,1938

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Patented Feb. 6, 1940 mmc'rron ENGINE Arthur" =W.:.Pope, Jr., Waukcsha, Wis., assignor to Wauke'shaMotor Company, Wankesha, Wis., a

of Wisconsin Application-September 1c, 1938, Serial No. 230,311

- "1 Claim.

This invention relates to injection engines, and has to do with, injection engines using electrical ignition means, such as 'glow plugs, for starting.

My invention is particularly directedto an engine of what may be termed the high swirl type, in which the fuel-air mixture is caused to rotate or swirl within the combustion chamber at high velocity, during normal operation of the engine. When starting such an engine, the swirl within the combustion chamber is relatively low and the injected fuel can readily pass across the chamber. I take advantage of that fact by disposing the heating element of a glow plug or analogous device at the opposite side of the combustion chamber from the injection nozzle, so as to receive the main portion of the fuel spray during the starting cycle. That facilitates starting, eliminating objectionable knocking and smoking at that time, and after starting the penetration of the fuel spray into the combustion chamber is reduced, due to the relatively high swirl then obtaining in that chamber. Thereafter the injected fuel does not impinge upon the heating element and the latter is effectively shielded from the violent flame swirl and high temperature within the combustion chamber, being appropriately located to that end. In that manner smooth starting of the engine is facilitated and.- the life of the glow plug or analogous device is materially increased.

In the drawing:

Figure 1 is a fragmentary axial sectional view through the upper end of a cylinder and a cylinder head of an engine, showing those parts with which imr invention is concerned, certain parts being shown in elevation; and

Figure 2 is a sectional view taken substantially on line 2-2 of Figure 1, on an enlarged scale.

I.have disclosed my invention, by way of example, as embodied in an engine comprising a cylinder 5, a piston 6 operating in the cylinder.

and a head I overlying the cylinder and secured thereover in an appropriate mannerjwith an intervening gasket 8. The cylinder 5 and the head I may be of any suitable construction and are water cooled in a known manner.-

bustion chamber 9. Plug 8 is provided with a restricted throat l opening into chamber 9 substantially tangent thereto, this throat opening at its lower end into the cylinder If desired, piston 6 may be provided, in its upper face, with a recess ll disposed adjacent the lower end of throat l0, when the piston is on the dwell of its compression stroke, for initially receiving the products of combustion ejected from chamber 9 through throat Ill. Plug 8 is further provided with an outer j substantially radial recess l2, which receives the inner end portion of a set screw l3 threaded into head I at one side thereof, this set screw serving accurately to position plug 8 and secure it in position.

Head 1 is provided with a stepped cylindrical bore l4 extending from an upper surface t'n ereof at an inclination downward and inward at the inner side of combustion chamber 9. Bore l4 receives a glow plug l5 of known type, which threads into the upper portion of bore I4, there being a gasket l6 interposed between a shoulder of plug l5 and a shoulder of bore I4. Body I! of plug I5 is of less length than bore M, the portion of the bore below body ll of the plug defining, with the lower end of the plug body, a pocket I8 which opens into combustion chamber 95 9, through an opening I!) in a plane of a chord thereof. Plug I5 is further provided with a depending coil 20 supported from body H in a known manner, this coil being disposed within pocket l8 with its lower end spaced an appreciable distance above the bottom. of the pocket.

An injection nozzle 2| is appropriately mounted in head I in a known manner, at the opposite side of combustion chamber 9 from pocket la. The nozzle may be of any suitable type, that 3 shown being a pintle type nozzle provided with a tip defining an injection port which may be coaxial with the nozzle, line ab indicating the common axis of the injection nozzle and of the port thereof. The lower end of pocket It defines, in the vertical plane of the line ab, a surface 22 extending outward from the lower end of. opening l9 parallel with and substantially in the horizontal plane of line ob, and a second surface 23 inclined upward and outward from surface 22. The nozzle 2| injects a spray of fuel into combustion chamber 9, along the line a.-b.

,When starting the engine, during travel of the .piston'fi inward on its compression stroke, air displaced from cylinder 5 is forced through throat ll! intocombustion chamber 9, in which chamber rotative or whirling motion at relatively low speed is imparted to the air, due to the tangential disposition of throat III. As piston 6 approaches fuel-air mixture surrounding and in contact with,

001120. When piston 6 is at or about its position of maximum compression, the fuel charge is ignited by the heat of compression supplemented by the heat of coil 20, it being understood that glow plug I is connected to a suitable source of electrical energy for heating coil 20, in a manner well known in the art. Disposing the heating element of the glow plug in the manner stated facilitates starting and-is conducive to. smooth-' ness and efllciency in operation.

After the engine has been started, and in the normal operation thereof, the swirl within the combustion chamber 9 is much higher than when starting. Consequently, the penetration of the fuel spray into the combustion chamber is materiallyreduced, and this spray; willnot reach the opening l9, the high swirl within the combustion chamber being then effective for shielding heating element or coil 20 from the injected fuel. Since coil 20 is outside of chamber 9, within pocket I8, it is shielded from the violent flame swirl and high. temperature within the combus- The useful life of the glow plug tion chamber. is thus materially increased.

It will be understood, of course, that valve controlled air inlet and burned gas outlet pasagw are provided, and that suitable means is provided for supplying fuel under pressure to the injection nozzle and timing the injection, as well as regulating the amount of fuel injected per working stroke of piston 6; all as is well known in the art.

I claim:

In an injection engine, a cylinder'and a piston operating therein, a head overlying said cylinder, a substantially spherical combustion chamber in said head opening into said cylinder through a restricted passage the upper end of which opens into said combustion chamber at the lower portion of and substantially tangent to one side thereof, an injection nozzle having a tip atsaid one side of said combustion chamber directly above said passage substantially in the vertical plane of the latter and disposed to inject a stream of fuel across said combustion'chamber toward the oppositeside thereof, said head havingapocket communicating with said combustion chamber 'at said opposite side thereof through an opening in a plane of a chord of said combustion chamber and substantially aligned transversely of the latter with thetip of said ARTHUR W. POPE, JR.

nozzle and said fuel stream, and electrical ignition 

